Method and means for casting slugs



Dec. 9, 1958 G. HARRISON 2,363,188

7 METHOD AND MEANS FOR CASTING SLUGS Filed Nov. 23, 1955 8 Sheets-Sheet1 Dec. 9, 1958 G. HARRISON 2,863,188

METHOD AND MEANS FOR CASTING SLUGS Filed Nov. 25, 1953 8 Sheets-Sheet 2I ma Inventor GEORGE HARRISO Dec. 9, 1958 4 G. HARRISON 3,

METHOD AND MEANS FOR CASTING SLUGS 'Filed Nov. 25, 1953 8 Sheets-Sheet 4Inventor 5 GEORGE HARRlSON www 'Dec. 9, 1958 G. HARRISON METHOD ANDMEANS FOR CASTING SLUGS 8 Sheets-Sheet 5 Filed Nov. 23. 1953 CNN OnN NaCNN Dec. 9, 1958 G. HARRISON 2,353,133

METHOD AND MEANS FOR CASTING SLUGS INVENTOR. Gaoresa HARRISON Dec. 9,1958 G. HARRISON 2,863,188

METHOD AND MEANS FOR CASTING SLUGS Filed NOV. 23, 1953 8 Sheets-Sheet 75 w 3 5 u ff! 9 2 2 o 4 J a a o: 5 5. E e I I: H

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Dec. 9, 1958 G. HARRISON METHOD AND MEANS FOR CASTING SLUGS 8Sheets-Sheet 8 Fil ed Nov. 2;, 1953 INVENTOR. G ORGE HAR nsou the moltenmaterial.

United States Patent O METHOD AND MEANS FOR CASTING SLUGS GeorgeHarrison, Chicago, Ill.

Application November 23, 1953, Serial No. 393,537

17 Claims. (Cl. 22-73) This invention relates to a method of, andapparatus for, making metal castings.

The invention has particular utility in the casting of metals and alloyshaving high melting points, such as aluminum and its alloys, wherein theprior art has experienced great difficulty in providing suitable,completely automatic, highly efficient, die casting machines. Theinvention has application, however, to the 'casting of metals having lowmelting points as well.

In the metal arts, many finished products are made originally from aslug of metal which is of a precise size and weight. It is one of theobjects of the present invention to provide a method of casting suchslugs which will result in a product of uniform composition and size.

It is another object of the present invention to provide a method ofcasting wherein the molten metal enters the cavity rapidly but yet witha minimum of turbulence.

This reduces the tendency for separation of the ingredients of themetal. As a result, the composition is so uniform throughout the entiremass of the casting that the casting may be used as a standard ofcomparison, as in spectrum spark analysis.

It is a further object of the invention to provide a casting machinewherein the dies are moved into position above a crucible of moltenmaterial to be cast and are filled by submerging the bottom of the dieassembly into It is a further object to provide a die casting apparatusof this type where the portion of the machine which contacts the moltenmaterial in the crucible is periodically and automatically removedduring each casting cycle to minimize the possibility of deteriorationby the hot molten material.

it is a still further object of the invention to provide a method andapparatus for casting wherein the die assembly remains in a position tocontinue to receive molten material from the crucible duringsolidification, and wherein the solidifictaion progresses toward theentry-way in the bottom of the molding die assembly.

In one embodiment of the present invention the casting is made in a coldmold, which is water cooled to keep it cold during the moldingoperation. To facilitate cooling of the water cooled mold themold body,with the exception of one face thereof, is made of copper or othersuitable high heat conductivity metal. The one face, which is not watercooled, is the bottom of the mold. The gate for the entry of liquidmetal into the mold is in this bottom face, which is maintained hotduring the molding operation. Liquid metal to be cast is introduced intothe mold at a controlled rate of flow to prevent turbulence andconsequent splashing of molten material onto the cold mold walls whichwould produce voids and irregularities at the casting surface.Preferably the mold is dipped into a body of molten material to be castand the air in the mold is evacuated at a controlled rate to draw moltenmaterial into the mold. The rate of exhaustion varies with the materialbeing cast and is adjusted to provide as high a rate of flow of materialinto the mold as is possible without creating undesirable turbulence.

ICC

The rate of exhaustion of the mold is preferably the main determinativefactor in the control of the rate of filling of the mold, rather thanthe hydrostatic pressure head of the molten material above the moldentry-way, so that the height of the unfilled portion of the mold doesnot materially affect the rate of flow of molten material therein.

As the liquid enters the mold and touches the water cooled side walls ofthe mold it solidifies. The rising mass of liquid metal is thereforesolidifying from the out side of the mold inwardly, and in the filledmold from the top of the mold downwardly, while the metal at the bottomof the mold is cooling much more slowly and therefore remains in itsliquid stage longer. This is accomplished by the cooling of the sidewalls of the mold cavity while maintaining the areas surrounding theentry way heated by contact with the hot molten material in the cruciblethat supplies the molten metal to the mold cavity. Because of theprogressive solidification of the metal toward the entry-way anyshrinkage of the solidifying metal results in drawing additional moltenmetal into the mold cavity so that upon ultimate solidification of themetal the resulting casting is devoid of cavities.

Briefly, the preferred form of the invention utilizes a composite dieassembly including an upper die element having an open bottom moldcavity, and a lower die element in the form of a preheated, open top,dish-shaped element which has a gate or entry-way in the bottom thereof.The upper die element is brought into engagement with the lower dieelement and the composite assembly is dipped into a body of moltenmaterial to be cast. The mold cavity (assuming there is only one moldcavity) is evacuated at a controlled rate which draws molten material ata fixed controlled rate into the mold cavity. This rate is preferablyjust short of the points where turbulence takes place. The upper dieassembly is cooled to cause progressive solidification of the materialin the mold cavity toward the entry-way while the die assembly remainsin contact with a large body of hot molten material. Following thesolidification of the metal in the mold cavity the die assembly is movedout of contact with the source of molten metal and the die elements aremoved transversely of each other to shear the casting from the slugremaining in the entry-way of the lower die element. The upper dieelement is then raised from the lower die element, whereupon an ejectingapparatus i s automatically moved into position between the separateddie elements and the slug remaining in the entry-way of the lower dieelement is ejected. The casting remains in contact with the upper dieelement. A chute is moved beneath the upper die element and then thecasting is released from the upper die element automatically at theproper time so as to drop, onto the chute, where the casting is carriedto a suitable disposal location.

The upper and lower die elements are moved by a hydraulic fluid operatedpiston device. The ejecting apparatus is moved by an air pressureoperated piston device. Since the ejecting apparatus is movedbetween theupper and lower die elements following their separation, safeguards mustbe provided to prevent collision with the die elements due to anyconditions which may tend to interfere with the proper timing ofoperation of these components. Specifically, a radical change intemperature or composition of the hydraulic fluid operating the pistondevice associated with the die assembly may change the speed at whichthe upper and lower die elements are moved toward and away from eachother, and hence may cause a collision between the ejecting apparatusand die elements. To safeguard against this condition, the operation ofthe air pressure actuated piston device associated with the ejectingapparatus is controlled by a valve member which in turn is actuated by acontrol arm ,3 which moves with the upper die element. The latter valvemember is actuated to move the ejecting apparatus into or away from aposition between the die elements only when the die elements are wellseparated from each other.

The attainment of the above and further objects of the present inventionwill be apparent from the following specification taken in conjunctionwith the accompanying drawings forming a part thereof.

In the drawings:

Fig. 1 is a side elevational view, in partial section, of the castingmachine of the present invention in the ejecting position;

Fig. 2 is an enlarged fragmentary front view, in'partial section, of themachine of Fig. 1;

Fig. 3 is an enlarged top view of the machine of Fig. 1;

Fig. 4 is an enlarged fragmentary side view of the machine of Fig. 1showing the elements of the machine in the die casting position;

Fig. 5 is a top view of the ejecting apparatus in Fig. 1;

Fig. 6 is a side view, in partial section, of the ejecting apparatus ofFig. 5;

Fig. 7 is a vertical section of the apparatus of Fig. 6 taken alongsection line 77;

Fig. 8 is a detailed, enlarged, vertical section of a part of the upperdie assembly;

Fig. 8a is an enlarged detail of a portion of the upper defining wall ofa mold cavity in the upper die assembly;

Fig. 9 is a diagrammatic view of the hydraulic, vacuum, and air linecircuits which control the operation of the casting machine;

Fig. 10 is a view corresponding to Fig. 8 and showing a modified dieassembly; and

Fig. 11 is a sectional view taken along the line 1111 of Fig. 10.

Reference may now be had more particularly to the drawings where likereference numerals indicate like parts throughout.

The casting machine 1 there shown, briefly, includes a movable framesupport member 6 which carrie a composite die assembly 8 comprisingrelatively movable upper and lower die elements 10 and 12, respectively,between which the castings are formed, ejecting apparatus 14 whichejects slugs from the lower die element 12, and control and timingapparatus 16 which controls in part, the sequence of operations of thevarious aforementioned elements of the casting machine.

The casting machine is associated with a furnace 2 which carries acrucible 4 of hot molten material to be cast. The stationary furnace 2comprises a raised, opentop, heat-insulated compartment 18. The lowerportion of the compartment is filled with burning gases fed thereto bygas lines 20 communicating therewith. The furnace element 2 includes anupper annular shoulder 22 on which rests a peripheral supporting flangeof the crucible 4. The crucible extends down into the compartment 18 ofthe furnace. Metal 26 in the crucible is maintained in a liquid state bythe heat of the flames in the bottom of the furnace compartment. Thefurnace 2 is raised from the floor by the legs 28.

The frame supporting member 6 of the casting machine 1 is mounted onwheels 30 that ride on rails 32 extending beneath the furnace 2 so thatthe entire machine can be moved from an operative position over thecrucible 4 to an inoperative position away from the crucible. The wheels30 are secured to the bottom of a lower base member 34, from whichextend a pair of vertical, upright, supporting members 36. A bracket 38is mounted on the two upright members 36 adjacent to the top thereof andsupports a horizontal frame base 40 which extends forwardly of andbetween the upright members 36. The frame base 4% supports a hydraulicdevice 42 which includes a piston that actuates the die assembly 8. Thebracket 38 also supports horizontal support members 44 and 46 that holdthe control and timing apparatus to be hereinafter described.

A movable frame assembly 50 is horizontally slidable in horizontalgrooves 48 in the sides of the frame base 40 and includes side framemembers 52 that are joined by front and rear bridge brackets 54 and 56,respectively, so that the connecting bridge brackets and the side framesconstitute a unitary structure that slides back and forth on the framebase 40. The side frames 52 include inwardly projecting rails 53 whichengage the walls defining the grooves 48.

A pair of dependent side plate members 60 are secured to the side framemembers 52 by bolts 59. The ejector apparatus 14 is mounted to thebottom of the plate members 60 between and forwardly of the uprightsupporting members 36.

The upper die assembly 10 includes a die block 69 and a water-air-vacuumdistribution block 71. This assembly is mounted on the bottom of avertically movable piston rod 64 that projects from the bottom of ahydraulic cylinder 68 of the hydraulic device 42. The blocks 69 and 71are bolted together and to a splitsleeve bracket 67, which bracket isclamped to the piston rod 64.

The die block 69 is made of a suitable highly heatconductive metal, forinstance, copper. It has, on the bottom face thereof, a plurality ofopen bottom die or mold cavities 70 which conform to the shape of thearticles to be cast. In the example illustrated in the drawings, thearticles are cylindrical disks.

Means is provided in the die block for applying vacuumto the moldcavities to control the rate of fiow of molten: material 'thereinto andfor applying air pressure thereto to aid in ejecting the finishedcastings from the die block. This includes the threaded bores 73 whichare formed in the block 69, one above each mold cavity 70, in each caseleaving a dividing wall 71' between the cavity and the bore 73.Vertically extending cylindrical holes 72 are formed in the wall 71',each hole 72 having a counterbored upper portion 74 in which the head 77of a plug 76 is located. The plug head 77 is spaced from the side wallsof the counterbore 74 and has circumferentially spaced nibs orprojections 79 depending from the bottom thereof to provide small spacesor passageways for the flow of air between the head 77 and the walldefining the bottom of the counterbore. Each plug 76 has a shank 81 thatfits within a hole 72 and terminates flush with the bottom of the wall71. The clearance between the shank 81 and the Wall defining the hole 72is small so that air, but not molten metal, may flow therebetween.

A plug of copper or other material of high heat conductivity is threadedinto each bore 73 in the upper surface of the die block 69. Verticalbores 78 extend through the plugs 75. The bores 78 slightly overlap theperipheries of the counterbores 74. The top of each plug 75 terminatesshort of the upper portion of the die block 69 so as to leave a cavitycommunicating with the bores in each plug 75. I

The distribution block is secured by screws to the top of the die block69. Bores 82 in the block 71, each centrally located above a plug 75,communicate at their bottom ends with the cavity 80, and at their topends with a horizontally extending air and vacuum channel 84. By meansof control valves and associated apparatus, to be described, alternatevacuum and air pressure are successively applied to each mold cavity 70via the channel 84, a bore 82, a cavity 80, bores 78 and the smallclearance space between the plugs 76 and the holes 72 and 74.

Means is provided for water cooling the block 10. This consists of aseries of vertical bores 88 extending from the top of the block 69 toadjacent the bottom thereof and surrounding each of the mold cavities 70as closely as is possible. The block 71 has a number of bores 88'extending upwardly from the bottom thereof and each res les bverlyingand communicating at its bottom with a bore 88 in the block 69. Theupper .ends of the bores 88 .are each connected to one or moremanifolding or cross bores 86. Above the manifolding bores 86 there isformed a series of interconnecting parallel bores 94 which areincommunicable with the bores 86. Communication with the bores 94isprovided by a series of tubes 92 that extend through the bores '88 andare threaded at their upper ends to the block 71 and open in the bore94.Each one of the tubes 92 extends into the bore 88 at its lower end withconsiderable clearance between it and the bore wall, and terminatesshort of the bottom of the bore 88. Cooling water, under pressure, iscirculated'through the water inlet duct 94 in the distribution block 71,thence through each of the tubes 92, thence through the space betweenthe tubes 92 and the bores 88 and 88 to the water outlet bore 86. Waterconduits or lines (shown diagrammatically in Fig. 9 to simplify thedrawings) are connected to the'ducts86 and94, respectively.

The piston rod 64 that carries the upper die assembly is movedvertically by a double acting piston in the hydraulic cylinder 68.Hydraulic lines 96 and 96 com rnunicate, respectively, with oppositeends of the cylinder 68 under control of a cam controlled valve 97 toeffect the reciprocation of the piston.

Apparatus is provided for accurately positioning the upper and lower dieassemblies with respect to each other during the filling of the moldcavities and for moving them laterally of each other following thesolidification of the castings to separate the castings in the upperdieassembly from connection with the lower die assembly. This apparatusincludes a vertically extending cam control rod 112 which is secured tothe rear of the split- -sleeve clampingbracket67 by a nut 110, and has across bar 114 which is secured to its-upper endas by a nut 113. Camrollers 116 are connected'to the ends ofthe cross bar by bolts 118 whichare threaded into the cross bar. As the piston of the hydraulic device42 reciprocates the upper die assembly 10, the rollers 116 arereciprocated therewith to actuate a pair of slotted cam plates 120 whichare fixedly secured to the side frame members 52 of the horizontallymovable frame assembly 50, thereby movingthe cam plates and with themthe frame assembly 50.

Each cam plate 120 includes a vertically extending slot 122 having aforwardly olfset lower portion 124. When the hydraulic device 42 movesthe upper die assembly and cam rollers 116 downward, the cam rollers 116enter the'cam slots-122 and, as the rollers ride in the lower portion ofthe cam slots 122, the cam plates 120 are .moved rearwardly by the camrollers. In so doing, the cam plates guide the lower die assembly 12,which is carried by the movable frame assembly 5d, into proper positionrelative to the upper die assembly.

When the upper die assembly 19 is in its lowermost p'osition (Fig. 4),the cam rollers 116 rest on the bottom of the cam slots 122. ln'thisposition, the casting opera- .tion, to be described, is performed.Following the formation of solid castings, the hydraulic device 42 movesthe cam rollers 116 upward, and the rollers 116 engage the upper portionof the cam slots 122. In so doing, the :rollers push the cam plates 12band the connected frame :assembly 5% forwardly relative to the upper dieassembly to separate the castings in the upper die assembly fromconnection with the lower die assembly. This operation will be describedin more detail hereinafter.

The lower die assembly 12 includes a flat bottom pan 130, made of asuitable high melting point alloy, and having upwardly extending sidewalls 131 and a fiat bottom 132. A plurality of gates or entry-ways 134having outwardly flared bottom ends extend through the bottom 132 of thepan 130, and are spaced the same distance apart as the centers of thedie cavities 70 in the upper .dieassembly 10. These entry-ways 134constitute sprues for the die molds. The pan 130 includes a peripheral 6flange 136 which rests on an annular shoulder 138 in a pan support ring140.

Pan guide bars 142 are provided on opposite sides of the hydrauliccylinder 68 and the bottoms thereof extend through apertures indiametrically opposite sides of the pan support ring 140. Nuts 144 arethreaded about the lower ends of the pan guide bars 142 from the bottomof the cam support ring to secure the pan guide bars 142 to the supportring.

Split collars 162 are secured to the bottom portions of the pan guidebars 142. A pair of similar split collars 164 are secured to the upperportions of the pan guide bars 142. The pan guide bars are supported in21 normally upper position by compression springs 168 which surround therespective pan guide bars 142 and abut the bottoms of the split collars164. The lower ends of the springs 168 rest against the upper surface ofrespective pillow blocks 170 which are secured to the side frame members52 of the horizontally movable frame assembly 50. A pair of lower pillowblocks 172 are secured to the side frame members 52 and act as stops forthe upwardly spring urged pan guide bars 142 by their abutment with theupper faces of the split collars 162. The compres sion springs 168normally bias the pan guide bars into a position where the bottom of thepan 130 is supported above the top of the crucible 4, as shown mostclearly in Figs. 1 and 2.

Before the machine is initially put into operation, the pan 130 isheated red hot, as by dipping the bottom thereof into the molten metalfor a time suificient to accomplish such heating. The machine is thenready for the initiation of the automatic casting operations. Theseoperations include the submerging of the bottom portion of the dieassembly into "the body of molten material in the crucible 4 .where themold cavities are filled with molten material rapidly and withoutturbulence, and Where the metal is caused to progressively solidify to-Ward the gates or sprues in the bottom of the assembly; and thesubsequent raising of the die assembly out of the crucible 4 and theremoval of the finished castings from the die assembly in a manner suchthat the castings are free of burrs and other undesirableirregularities.

In the mold cavity filling operation, it is desirable that the rate offlow of molten material into each mold cavity be determined mainly bythe rate of exhaustion of each mold cavity rather than by thehydrostatic pressure head of the body of molten material above thebottom of the unfilled portion of each mold cavity. In the latterinstance, the rate of fiow of molten material into each mold cavitywould vary with the depth of submergence of the bottom of the moldcavity below the surface of the molten material in the crucible 4, andwith the rising of the molten material within each mold cavity. Thus,where the rate of filling is determined mainly by the hydrostaticpressure head, and the rate of exhaustion of the mold cavities isadjusted to a point just short of the point creating turbulent flow whenthe mold cavities just begin to fill with molten material, the rate offlow of material into the cavitiesdecreases as the mold cavitiesgradually fill so that much valuable time is lost and ti e processbecomes inefiicient. Therefore, to minimize the time required to fillthe mold cavities and the effect of the depth of submcrgence of the dieassembly in the crucible, the depth of submergence of the die assemblyin the crucible is reduced to a value where the rate of exhaustion ofthe mold cavities primarily determines the rate of flow of the moltenmaterial therein. Where the mold cavities have a constant horizontalcross sectional area, as the cylindrical castings illustrated in thedrawings, the rate of exhaustion of the mold cavities necessary to fillthe cavities at a constant and rapid rate just short of creatingturbulence is a fixed and constant amount for a given casting material.A variation in the viscosity and surface tension of the casting materialvaries the flow characteristics thereof. and the rate of cavityexhaustion necessary to provide a rate offlow into the mold cavitiesjust below the rate creating undesirable turbulence. In any particularcase, this rate of cavity exhaustion may be determined experimentally byrunning several trial runs.

The casting operation performed by the machine is as follows:

The actuation of a cam controlled valve initiates the operation of thehydraulic device 42 to effect the downward movement of the die block 69and the distribution block 71. The die block 69 is moved downward firstinto engagement with the bottom of the pan 130 and, upon continueddownward movement, moves the pan 130 downward against the force of thesprings 168 into the molten material 26 in the crucible 4. The upperportion of the pan 130 remains above the molten material. The engagementof the cam rollers 116 with the bottom of the slots 122 of the camplates 120 accurately positions each of the die cavities 70 of the upperdie assembly over one of the entry-ways 134 of the pan 130. The moltenmaterial then enters each mold cavity through its entry-way 134 at arate inhibiting turbulence as controlled by the rate of evacuationthereof by a source of low pressure connected to the top of each moldcavity through the clearance space between the plug 76 and the hole 72.The molten material rises in each mold cavity as air is exhausted fromthe unfilled portion thereof. When the molten material reaches the topof each mold cavity, which is the bottom face of the wall 71, entry ofmolten material into the cavity comes to a halt since the moltenmaterial is unable to enter the small space between the plug 76 and thewall of the hole 72 in the top cavity wall 71.

The solidification of the metal is then effected while the mold assemblyremains partly submerged below the surface of the molten material 26.The molten metal filling each mold cavity solidifies progressivelytoward the entry-ways 134, since the side and top mold Walls are watercooled and thetpan bottom is maintained in contact with the hot body ofmolten material 26. Any shrinkage of metal in the cooling of the liquidmetal will be taken up by the liquid metal beneath the solidified metal,which liquid metal is in turn replaced by metal drawn into theentry-ways 134 from the main body of molten material 26. The progressivesolidification of the metal in the mold cavities and the non-turbulentflow of liquid metal therein produces cast products of homogeneouscomposition.

After the metal solidifies through the entry-ways 134, the hydraulicdevice 42 raises the composite die assembly out of the crucible 4. In sodoing, the cam plates 120 are moved forwardly by the cam rollers 116 asthe rollers move into the upper portion of the cam slots 122. Thisoccurs prior to the separation of the die block 69 from the pan 130 sothat the pan is moved laterally of the die block 69 to shear thecastings 71 in the die block cleanly from the solid slugs 179 within thepan entryways 134. The slugs and castings are separated along ahorizontal plane which is coextensive with the fiat bottom of the pan130 so that the separated castings have a smooth bottom surface. Thisinsures that the castings have a uniform shape and quantity of materialvJust prior to the separation of the die block 69 from the pan 130, avery low pressure is applied to the top of the mold cavities to securethe castings to the die block 69 by suction so that upon separation ofthe die block from the pan the castings remain with the die block.

When the hydraulic device 42 has moved the die block 69 to its uppermostposition, the control arm 98 projecting from the rear of the hydrauliccylinder 63 actuates the control rod 102 of a valve 100 which is securedto the movable cam control rod 112. This initiates movement of theejecting apparatus 14 into a position between the die block 69 and thepan 130. The slugs 179 in the pan entry-ways 134 are then ejected andthe castings removed from the die block 69.

The avoidance of a collision between the ejecting apparatus 14 and theupper die assembly 10 is assured, since the movement of the ejectingapparatus toward the die assembly is controlled by the position of theupper die assembly. The speed of movement of the hydraulic apparatus 42which moves the upper die assembly 10 varies somewhat with the viscosityof the hydraulic fluid so that collision between the upper die assemblyand the ejecting apparatus is possible if the movement of the ejectingapparatus 14 is not controlled by the actual position of the upper dieassembly.

The ejecting apparatus 14 includes a horizontal supporting base member180 which extends between, and is bolted to, depending side platemembers 60 of the horizontally movable frame assembly 50. The ejectingapparatus thus moves as a unit with the pan under the control of the camplates 120 to insure a proper and constant orientation between the panand the ejecting apparatus. The base member has an inverted T-shapedslot 181 which slidably receives a rectangular shaped gib 183 in thebottom thereof. Extending into the slot 181 and secured to the top ofthe gib 183 is a chute support member 206 which has an inclined upperrear surface 207 on which rests a forwardly and upwardly inclined chute209 secured for movement with the chute support member. The chute 209has upwardly extending side walls 211 defining the sides of a channelfor guiding completed castings dropped thereon from the upper dieassembly 10 to a storage bin.

The front end of the chute support member 206 is connected to a pistonrod 192 of the piston actuated device 188 by a plate 196 from whichextends a stud 198. The stud is received in an opening in the piston rod192 and is held in place within the opening by any suitable means, suchas by the cotter pin 199. The plate 196 is bolted to the chute supportmember.

A cylinder mounting bracket 182 is secured to the ejector base member180 and it has an upwardly extending arm 184 at the rear thereof. Thearm 184 has an aperture to receive a pivot pin 185 projecting beyond theouter faces thereof. The air actuated device 188 has a cylinder 190which is supported on the pivot pin 185 by means of spaced aperturedears or lugs 193 which straddle the arm 184 and receive the pin 185.Longitudinal movement of the pivot pin 185 relative to the mountingbracket 182 is prevented by a cotter pin 194 extending through aperturesin the ends of the pivot pin 185. The cylinder 190 rests on a shoulder191 on the mounting bracket 182 which insures a horizontal orientationof the piston rod 192 projecting forwardly from the front end of thecylinder 190.

A piston is mounted within the cylinder 190 in a conventional manner andactuates the piston rod 192 and the gib 183, chute support member 206,and chute 209 forwardly and backwardly with it.

The device 188 is air actuated and the air inlet lines 106 and 108 (Fig.9) associated with the valve 100 communicate with opposite ends of thecylinder to actuate the piston therein in opposite directions.

A carrier plate 200 is secured to the end of the chute support member206 and it has laterally extending arms 202 projecting from oppositesides of the forward end thereof. The front, outer ends of the crossarms 202 are cut away at 204 to provide a curved abutment against whichthe pan guide bars 142 rest when the carrier plate 200 is in itsforwardmost position, as shown in Figs. 5 and 6. This accuratelypositions the carrier plate 200 with respect to the pan 130. An airactuated slug-ejecting device 240, to be described, is supported fromthe front end of the carrier plate 200.

When the upper die assembly 10 is in its uppermost position and thecontrol arm 98 has depressed the control rod 102 of the valve 100, airpressure is applied to the right-hand end of the cylinder 188 (Figs. 1and 5) via air input line 104 and air output line 108 and the piston 192is moved to the left, thereby carrying the ejecting device 240 and thechute 209 with it into operative position between the upper and lowerdie assemblies and 12. When the die assembly 10 is in a position otherthan its uppermost position, the valve rod 102 is out of engagement withthe control arm 98 and the air input line 104 is connected to the line.106 leading to the left-hand side of the cylinder 188 which moves theejecting apparatus to the right out of the way of the upper dieassembly.

The air actuated ejecting device 240 includes an airoperated cylinder242, a movable piston 244 therein, and a depending piston rod 246 whichcarries on the bottom thereof upper and lower ejector plates 248and'250. The upper and lower ejector plates are bolted together. Thedepending pin members 252 are secured to the lower ejector plate 250 andare spaced to overlie the respective apertures 134 at the bottom of thepan 130.

Air input lines 256 and 258 (see Fig. 9) are connected, respectively,with the upper and lower ends of the cylinder 242 for reciprocating thepiston 244 therein. Air under pressure is alternately applied to the airinlet lines 256 and 258 under the control of a cam operated air valve260, to be hereinafter described. At the appropriate moment followingthe positioning of the ejecting apparatus above the pan 130, air isapplied through the air line 256 to the upper part of the cylinder 242to force the piston 244 downward, thereby carrying ejector pins 252 intothe pan apertures 134. The solid slugs 179 in the apertures 134 arethereby pushed into the crucible 4, where they are re-melted.

To assure accurate orientation of the ejector pins 252 with respect tothe pan apertures 134, a guide rod 262 is secured to the ejector carrierplate 200 and it extends through a guide aperture 264 in the upperejector plate 248. The guide rod secures the ejector plates 248 and 250against rotation about the axis of the piston rod 246 and thus itmaintains the alignment of the pins 252 with the pan apertures 134.

Following the ejection of the slugs 179, the cam controlled air valve260 shuts off the supply of air pressure to the air line 256 and appliespressure to the line 258, thereby raising the piston rod 246 andattached ejector plates and pins out of the pan 130. The ejectingapparatus is then retracted rearwardly of the machine and out of thepath of movement of the upper die assembly as the valve apparatus, to bedescribed, initiates another casting operation which begins with thedownward movement of the upper die assembly 10. Valve apparatus isprovided for controlling the pressure in the die cavities. Thisapparatus includes valve members 214 and 216 which are secured to theejector apparatus mounting bracket 182. These valve members includemovable control rods 218 and 220, respectively, which, when the chute209 is in its forwardmost position where it underlies the upper dieassembly 10, abut a movable control arm 230 depending from, and movablewith, the chute 209. This actuates the valves 214 and 216 to effect theinterruption of the vacuum applied to the mold cavities 70 in the dieblock 69 and the application of a relatively high air pressure theretoto eject the solid castings. Since the actuation of the valves 214 and216 is controlled directly by the control arm 230 moving with the chute209, ejection of the castings from the upper die assembly 10 occurs onlywhen the chute 209 is in position to receive the castings.

Connected to the air valve 216 (see Fig. 9) is an air inlet line 236 andan air output line 238 connecting the die cavities 70 of the upper dieassembly 10 via line 239. The air input and output lines 236 and 238 areinter connected by the air valve member 216 to apply high pressure tothe mold cavities when the control rod 220 thereof is in contact withthe control arm 230, which, as

stated above, occurs when the chute 209 is moved bee neath the upper dieassembly.

A vacuum input line 232 and a vacuum output line 234 connect with thevacuum valve 214. When the control rod 218 is removed from the controlarm 230 by the rearward movement of the chute 209, the vacuum valve 214connects the vacuum input line 232 with the vacuum output line 234. Thisapplies low air pressure to the mold cavities of the upper die assembly10 via the line 239 to exhaust the air in the mold cavities 70 to drawmolten material therein, in a manner previously explained. The inputline 232 is connected with a vacuum header line 241 and vacuum pump 270through the valve 215 or, alternatively, through an adjustable bleedervalve 257 connected across the valve 215.

The adjustable bleeder valve 257 may be a conventional needle-valvewhich may be adjusted in small in cremental amounts between a positionwhere the valve is almost completely closed and a position where thevalve is completely open. -In this manner the value of low pressure atthe output side of the needle valve 257 may be adjusted between vacuumor the low pressure output ofvacuum heater line 241 and, say,atmospheric pressure. The adjustable bleeder valve 257 determines thelow pressure condition of the mold cavities 70 during the fillingoperation and so controls the rate of filling of these cavities in amanner previously explained. The vacuum valve 215 remains closed duringthe filling of the mold cavities so that the bleeder valve 257 will thencontrol the pressure in the mold cavities. The needle valve is adjustedby a trial and error method, to a posi tion where the rate of exhaustionof the air from the mold cavities causes a rate of flow of moltenmaterial therein which is just short of the point where the turbulenceof the in-flowing molten material forms air holes and irregular surfacesin the finished castings.

A gauge 259 connected at the output of the bleeder valve 257 indicatesthe pressure at this point. The gauge will indicate when the moldcavities are full since the pressure will then suddenly drop due to thetermination of the rise of molten material in the mold cavities.

The bleeder valve 257 is by-passed when the vacuum valve 215 is openedby the timing and control apparatus 16. The opening of the vacuum valve215 applies the lowest air pressure available in the header line 241 tothe mold cavities to provide maximum suction so as to maintain the solidcastings in the mold cavities following the separation of the upper andlower die assemblies.

As previously stated, the sequence of operations of the various parts ofthe casting machine thus far described is controlled by the timing andcontrol apparatus indicated generally by the reference numeral 16.

The timing and control apparatus 16 includes a synchronous motor 261which is supported on the horizontal support member 44 associated withthe bracket 38. A vacuum pump 270 is supported on the member 46. The

motion of the shaft of the motor 261 is coupled to the shaft of a vacuumpump 27% by a belt 266 which engages the grooved wheels 262 and 268,respectively connected to the shafts of the motor 261 and the vacuumpump 270. The motion of the motor shaft is also coupled to a speedreducing device 278 by means of the belt 264 which engages the groovedwheel 262 and the grooved wheel 274, connected to the shaft 276 of thespeed reducing device 278. Through suitable gearing within the speedreducing device 278 respective cams 280, 282 and 284 are slowly rotatedon a common shaft and actuate, respectively, the hydraulic control valve97, the air pressure valve 260, and the vacuum valve 215. Each of thevalves includes respective control rods 290, 292 and 294 which ride onthe peripheries of the cams 286, 282 and 284. These cams areappropriately shaped so that during a single rotation of said cams, thecontrol rods 290, 292 and 294 are depressed for a predetermined portionof the casting cycle to properly control the sequence of operations of11 the various movable elements of the casting machine. The cam 280actuates the valve 97 which controls the movement of the upper dieassembly.

The hydraulic control valve 97 (see Fig. 9) is coupled to a source ofhydraulic fluid, such as oil, through a hydraulic input line 298. Thehydraulic lines 96 and 96 are coupled between the output side of thevalve 97 and the upper and lower portions, respectively, of thehydraulic cylinder 68. To initiate the downward movement of the upperdie assembly, the cam 280 depresses the control rod 290 which connectsthe hydraulic input line 298 to the hydraulic line 96 through the valve97 to carry hydraulic fluid t the upper end of the hydraulic cylinder68, thereby moving the piston therein downwardly. The oil previouslyfilling the bottom of the cylinder 68 is removed via the line 96 andreturn line 302.

When the piston has reached its lowermost position, the castingoperation previously described is performed. At a given time after theinitiation of the downward movement of the piston within the hydrauliccylinder 68, said time occuring after the complete solidification of themolten material within each die cavity 70, the cam 280 allows thecontrol rod 290 of the valve 97 to move outwardly, thereby causing thehydraulic input line 298 to be connected to the hydraulic output line96. The hydraulic fluid is then coupled to the bottom of the hydrauliccylinder 68 thereby moving the piston upward in the hydraulic cylinder68 which moves the die block out of engagement with the pan 130 toterminate the casting operation. The hydraulic fluid in the upperportion of the cylinder 68 is removed via the hydraulic line 96 andreturn line 302.

A hydraulic valve 291, similar to the valve 97, and having ahand-operated control rod 293, is connected in parallel with thehydraulic valve 97 so that the die assem blies 10 and 12 can begradually operated to lower the pan 130 into the crucible 4 where it isheated red hot (for reasons previously explained), before the machine isplaced into automatic operation.

The cam 2S2 actuates the valve 260 which controls the operation of theslug-ejecting mechanism 240. The air header line 107 connects with theinput side of the air pressure valve 260. When the ejecting device 240has been moved to a position over the pan 130, following the terminationof a casting operation, the cam 282 actuates a control rod 292 of thevalve 260 and the air line 107 is connected to the air line 256 leadingto the upper end of the cylinder 24 2, thereby moving the ejecting pins252 downward. The cam 2S2 actuates the con trol rod 292 in the oppositedirection following the ejection of the slugs from the entry-ways 134 ofthe pan 130, by connecting the air header line 107 to the other A reviewof the sequence of operations of the various components of the castingmachine is as follows: After the pan 130 has been heated red hot, andunder the control of the cam-operated hydraulic valve 97, the upper dieassembly is moved downward to initiate a new casting operation. With theinitiation of the downward movement of the die block 69, the valve 100is actuated by the removal of the control rod 102 from contact with thecontrol arm 98 which causes air under pressure to be fed to the lefthand side of the cylinder 190 associated with the ejecting apparatus 14,to move the ejecting apparatus rearwardly or away from the pan 130. Thedie block 69 then depresses the pan 130 into the molten material 26 inthe crucible 4 in its downward movement, whereupon the mold cavities 70begin to rapidly but without turbulence fill with molten material due tothe evacuation of the mold cavities, the adjustable needle valve 257having been previously adjusted to provide a maximum non-turbulent rateof flow of the molten material into the mold cavities. After thecavities have been filled and the casting material has solidified, thevacuum control valve 215 is opened which applies vacuum to the moldcavities. The hydraulic valve 97 is actuated by the earn 280 to move thedie block upward. This carries the spring biased pan 130 upward with it.Then, as the cam rollers 116 engage the upper portion of the cam slots122, which occurs prior to the separation of the pan and the die block,the cam is shifted laterally with respect to the die block 10 to shearthe castings from the slugs in the pan entry-ways 134. When the dieblock 69 has been raised to its uppermost position, the control rod 102of the valve 100 is depressed by the control arm 98, which actuates thepiston-operated device 188 to move the ejecting apparatus 14 intooperative position between the die block 69 and the pan 130. Valves 216and 214- are then actuated and vacuum is removed from the mold cavities70 and air pressure is applied to eject the castings from the moldcavities, which fall onto the chute 209 on which they slide, by gravity,from the machine. A new casting cycle is initiated by the cam 280 as itactuates the valve 97 to begin the downward movement of the die block69, following ejection of the slugs from the pan entry-ways and theremoval of the castings from the die cavities 70.

The vacuum method of retaining the solid castings to the upper dieassembly 10 following the separation of the upper and lower dieassemblies may be unsatisfactory where the solid castings are ofappreciable weight or where the top surface of the castings are curved.In such case, the upper die assembly may be modified by providing anundercut portion in each mold cavity as by reducing air line 258, whichconnects with the lower end of the cylinder 242 to raise the ejectorpins 252 from within the pan 130.

The cam 234 actuates the valve 215 to control the timing of theapplication of suction to the die cavities 70 to maintain the finishedcastings to the upper die assembly when the upper die assembly separatesfrom the pan 130. As previously stated, the valves 215 and 257 are inparallel, and together are in series with the valve 214 which connectswith the line 239 leading to the air and vacuum channel in thedistribution block 71. When the molten material in the mold cavities 70has solidified, and just prior to the separation of the lower and upperdie assemblies, the cam 284 actuates the control rod 294 of the valve215 to open the valve and connect the vacuum header line 241 directlywith the line 232. At that time, the control arm 230 has been removedfrom the control rod 218 of the vacuum valve 214, so that the valve 214couples the line 232 to the line 239 leading to the distribution block71 where vacuum is applied to the upper portion of the mold cavities tosecure the mold castings to the upper die assembly by suction.

the size of the bottom opening in each mold cavity to produce an annularshoulder or seat on which each casting sits. The ejection of eachcasting from the upper die assembly may be effected by means of one ormore ejector pins which force each casting through the narrowed openbottoms of the die cavities.

Such a modified form of die assembly is shown in Figs. 10 and 11 towhich reference should now be had. The basic elements of this modifiedupper die assembly 10 include a lower die block 300 having mold cavities301, a pair of intermediate distribution blocks 302 and 304 which aid indirecting cooling water, air pressure, and vacuum to the die block 300,and a pair of upper cylindrical members 306 and 308 which together forman air-operated piston device which vertically reciprocates dependentejector pins 310 into and out of the mold cavities 301 to eject thesolid castings therefrom. All of these components are connected togetherand are secured to the piston rod 64 by the split sleeve 67.

The mold cavities 301 are open at their bottoms and,

in the illustrated embodiment, have non-circular crosssections. Thecavities shown have vertically extending side walls which flare inwardlyslightly at the open bottoms of the cavities so that the mold cavitiesundercut sjseai'ss slightly the neck portions 313 defining the openingsinto the bottoms of these cavities. The width of the necks 313 should beof such a value or, in other words, the amount by which the upperportion of the mold cavities undercuts the open bottoms thereof shouldbe such that shrinkage of the metal in the mold cavities uponsolidification thereof provides a press fit between the outer verticalwalls of the castings and the necks 313 so that the castings are securedto the necks 313 by the friction therebetween. The castings may then bereadily ejected from the'mold cavities by the downward movement of theejector pins 310 against the tops of the castings.

The upper portion of the die block 300 has vertically extending bores314 which communicate with the tops of the mold cavities 301 and receivethe vertically movable ejector pins 310 depending from a piston 316located in the upper portion of the upper die assembly. As illustrated,each mold cavity has several of these bores and ejector pins associatedtherewith. A small clearance is provided between the ejector pins 310and the walls defining the vertical bores 314 so as to prevent the riseof molten material while allowing the passage of air therebetween. Thebores 314 also serve as passageways for the application of vacuum to themold cavities 301 to control the rate of flow of molten materialthereto.

To effect the circulation of cold water through the die block 300, anundulating horizontally extending slot 318 is cut in the upper face ofthe die block 300, to provide a passageway for cold water whichtraverses the portion of the die block above the mold cavities 301. Agasket 320 overlies the top surface of the die block 300 and covers theopen tops of the slots 318 to provide a closed passageway for thecirculation of the cooling medium. The gasket is provided with openingsto receive the ejector pins 310.

Above the gasket 320 is situated the lower distribution block 302. Thedistribution block 302 includes water inlet passageway 322 whichcommunicates with one end of the die block slot 318 through a suitablyplaced aperture in the gasket 320. The lower distribution block alsoincludes a water outlet passageway 324 which communicates with the otherend of the die block slot 318 through an aperture in the gasket 320.Cooling water is thus circulated through the upper die assembly via apath including the water inlet passageway 322', the die block slot 318and the water outlet passageway 324. The die block 300, as is the dieblock 69 previously described, is made of a highly heat conductivematerial such as copper, so that the walls of the mold cavities 301 arecooled to efiect a progressive solidification of the molten materialwithin the mold cavities toward the entry-ways in the pan 130 associatedwith the lower die assembly.

The lower distribution block 302 also includes vertical bores 328 whichare in register with the bores 314 in the die block so as to receive theejector pins 310. clearance is provided between the ejector pins 310 andthe walls defining the bores 328 to enable air to pass therebetween.

The lower distribution block 302 also includes an air receivingpassageway 330 having open endsrespectively in the side and top faces ofthe distribution block. The opening of the passageway 330 whichcommunicates with the upper face of the lower distribution block 302communicates with a cylindrical cavity 332 formed in the bottom face ofthe upper distribution block 304. The cavity 332 is in communicationwith each of the bores 328 in the lower distribution block 302.

The upper distribution block 304 also includes vertical bores 336 whichslidably receive the ejector pins 310. An annular gasket 338 is insertedbetween the peripheral abutting portions of the upper and lowerdistribution blocks to effect an air-tight seal therebetween.

The upper and lower distribution blocks thus provide together aplurality of communicating passageways which communicate with the top ofthe die cavities through A small i4 the passageway 330, cavity 332, andbores 328 and 314. The air and vacuum line 239 is connected to. theinlet end of the passageway 330 in the lower distribution block 302. Thevacuum is thereby applied to the mold cavities 301 to exhaust the airfrom the mold cavities to effect the fiilling thereof in a mannersimilar to that previously explained in connection with the embodimentof Figs. 1 through 9. Air pressure is applied to the mold cavities viathe same path during the ejection of the castings to remove any dustparticles gathering in the spaces between the ejector pins 310 and thebores 328 and 314.

'The ejector pins 310 have enlarged heads 340 which are seated in andthreaded to the walls defining the counterbores 342 in the upper face ofthe piston 316. The piston 316 is vertically movable within a verticalcylindrical bore 318 formed in the hollow cylindrical member 308. In theuppermost position of the piston 316, the bottoms of the ejector pinsare flush with the tops of their associated mold cavities. With thepiston in its lowermost position, the bottoms of the ejector pins extendwell down into the mold cavities as shown in Fig. 10.

The bore 318 is open at its bottom end. A gasket 344 is fitted betweenthe bottom of the hollow cylindrical member 308 and a cylindrical plateor block 306. The plate 306 and the gasket 344 have bores in registrywhich receive the shanks of the ejector pins 310. The plate 306 rests onthe upper distribution block 304. A cylindrical recess 346 which isvented to the atmosphere is formed in the bottom face of the plate 306and receives a plurality of annular gaskets 348 which surround theportion of the ejector pins extending therethrough and which abut theopposed faces of the plate 306 and the upper distribution block 304. Thegaskets are under compression and effect an air-tight seal with theadjacent walls of the ejector pins, plate 306 and the upper distributionblock 304. The gaskets prevent the leakage of air between the pistoncontaining bore 318 and the cavity 332.

The piston 316 is reciprocated by means of air pressure appliedalternately above and below the piston 316 within the piston containingbore 318. A passageway 350 in the side walls of the hollow cylinder 308communicates with the upper portion of the bore 318. A passageway 352formed in the plate 306 communicates with the bottom of the bore 318.The passageways 350 and 352 are connected to a cam operated valve drivenby the motor 261 which applies air pressure at the appropri ate times tothe passageways 350 and 352 to alternately move the piston 316 upwardand downward in the bore 318. One of the passageways is connected by thevalve to the atmosphere while the other passageway is connected to asource of air under pressure.

The operation of the casting ejecting portion of the upper die assemblyis as follows:

The upper die assembly 10', with the ejector pin bottoms flush With thetop wall of the mold cavities, is moved into engagement with the pan andinto the crucible 4 where the mold cavities 301 are filled by evacuatingthe air therefrom through the bore 314. Following the filling of themold cavities and the solidification of the molten material therein, theupper die assem bly 10 is raised from the pan 130. The solid castingsare maintained within the mold cavities by a tight fit between the necks313 at the open bottoms of the mold cavities and the outer walls of thecastings. The castings may then be readilyejected from the mold cavitiesby the downward movement of the ejector pins into the bottom of the moldcavities which forces the castings out of the open bottoms of the moldcavities. Following the ejection of the castings, the piston 316 ismoved into the upper portion of the piston cylinder 318 and the abovedescribed process is repeated.

The invention thus provides a relatively simple and efficient method andapparatus for making a large number of smooth surfaced castings whichare of uniform composition and shape throughout.

It should be understood that numerous modifications may be made of thepreferred embodiments of the invention above described without departingfrom the broader aspects of the invention.

I claim:

1. Casting apparatus comprising a die assembly having separable upperand lower die elements adapted, when brought together into confrontingrelation, to define a mold cavity which conforms in shape to the articleto be cast, means for supporting said die assembly above an open topcontainer which holds a body of molten material to be cast, said lowerdie element being an open top, dish-shaped element with a flat bottomand up standing side walls and having at least one aperture extendingthrough the bottom thereof forming a mold cavity entry-way, said upperdie element having a mold cavity portion open at the bottom and shapedto enable the ready removal of the article to be cast through the openbottom thereof, means for moving said upper die element into engagementwith said lower die element with the open bottom of said upper dieelement abutting the bottom of said lower die element, with saidentry-way communicating therewith, and for depressing said lower dieelement into the molten material in the container with the top of theside walls thereof being above the level of the molten material in thecontainer, said last-mentioned means being adapted to move said upperdie element out of engagement with said lower die element following thesolidification of the molten material in said mold cavity, means formoving one of said die elements laterally with respect to the other toshear the slug in said entry-way from the remainder of the casting,means for retaining the solid casting in said upper die elementfollowing the separation of the upper and lower die elements, and meansforremoving the casting from the open bottom of the upper die element.

2. Casting apparatus comprising a frame member being adapted to overliean open top container containing molten material to be cast, a dieassembly depending from said frame member and including a lower dieelement having an apertured bottom and an upper die element having atleast one mold cavity which is open at the bottom and being shaped toenable the ready removal of the article to be cast through the openbottom thereof, an aperture in the top of said mold cavity which ispervious to the passage of air but impervious to the passage of saidmolten material therethrough, first means for moving said upper dieelement into engagement with the lower die element with the aperture inthe lower die element bottom communicating with the mold cavity, saidfirst means being adapted to further move said lower die elementdownward into the molten material in the said container, second meansfor connecting a source of adjustable air pressure to said upper diecavity aperture to control the rate of flow of molten material into thesaid mold cavity, third means for separating said upper die element fromthe lower die element following the complete solidification of thematerial in said mold cavity, fourth means for retaining the solidcasting within the cavity of the upper die element following theseparation of the upper and lower die elements, and fifth means forremoving said casting from the open bottom of said upper die elementmold cavity following the separation of said die elements.

3. Casting apparatus comprising a frame member being adapted to overliean open top container containing molten material to be cast, a separabledie assembly depending from said frame member and including a lower dieelement having an apertured bottom and an upper die element having atleast one mold cavity which is open at the bottom and being shaped toenable the ready removal of the article to be cast through the openbottom thereof, an aperture in the top of said mold cavity which ispervious to the passage of air but impervious to the passage of saidmolten material therethrough, first means for moving said upper dieelement into engagement with the said lower die element with theaperture in the lower die element bottom communicating with the moldcavity, said first means being adapted to further move said upper dieelement and lower die element downward into the molten material in thesaid container, second means for connecting a source of air pressure tosaid upper die cavity aperture in the top of said die element moldcavity to control the rate of flow of molten material into the moldcavity, third means for moving said upper die element from the lower dieelement following the complete solidification of the material in saidmold-cavity, fourth means for connecting a source of very low pressureto said aperture in the top of said mold cavity prior to the separationof said die elements and following the solidification of the moltenmaterial in the die cavity to retain the solid casting within the cavityof the upper die element by suction, and fifth means for disconnectingsaid source of very low pressure from said upper mold cavity aperture torelease the solid casting therefrom following the separation of said dieelements.

4. A casting machine comprising separable die elements which, whenbrought into engagement, define a mold cavity having an entry-wayextending through the bottom of one of the die elements andcommunicating with the mold cavity, first means for moving saidseparable die elements from a position wherein the elements aredisplaced from one another and are out of contact with a body of moltenmaterial, into a position wherein the die elements are in engagement andthe bottom of the assembly is immersed into a body of molten material,said first means also being adapted to remove said die assembly fromcontact with the body of molten material and to separate the dieelements from each other following the solidification of the moltenmaterial in the mold cavity and said entry-way, an ejecting device forejecting slugs from said entry-way, a finished casting receiving member,second means for moving said ejecting device and finished castingreceiving member from a position displaced from said die elements to aposition between the separated die elements with the ejecting deviceadjacent to the die element having said entry-way and said finishedcasting receiving member adjacent to the other die element, third meansfor maintaining the solid casting secured to said latter die elementfollowing the separation of said die elements, first control meansresponsive to the separation of said die elements to cause said secondmeans to move said ejecting device and finished casting receiving memberbetween the separated die elements, said first means also beingresponsive to the movement of said die elements toward each other tocause said second means to move said ejecting device from between theseparated die elements, second control means responsive to the positionof said finished casting receiving member opposite said other dieelement to cause said third means to eject a solid casting from saidother die element, third control means for periodically actuating saidfirst means to move said die elements into the body of molten materialand for causing said first means to raise said die assembly from thebody of molten material and to separate said die elements following thesolidification of the molten material in said die cavity, and fourthmeans responsive to the upward movement of said die assembly from thebody of molten material for moving one of said die elements laterallywith respect to the other die element to shear the main body of thesolid casting from the slug remaining in said entry-way.

5. The casting machine of claim 4 wherein one of the die elementsconstitutes an upper die element having an entry-way extending throughthe top thereof for communication with the die cavity. and the other dieelement constitutes a lower die element having said first mentionedentry-way therein, a source of very low pressure for connection to saidentry-way at the top of the upper die element to retain the solidcasting in said upper die element, said second control means including arelatively stationary control element and a removable control elementwhich is movable with said finished casting receiving member, saidlatter control elements making engagement when the finished castingreceiving member has been moved opposite the upper die element tothereby disconnect said source of low pressure from said entryway at thetop of said upper die element to cause ejection of the solid castingpreviouslyretained thereby by the suction applied by the source of lowpressure.

6. A casting machine comprising a mold having mold elements movablymounted with respect to each other and defining an enclosed mold cavitytherebetween, an entry-way to said mold cavity in one of said moldelements, means for bringing said mold elements together and for dippingsaid mold into a body of molten material with said entry-way immersedtherein, means for filling said mold cavity through said entry-way,means for raising said entire mold out of said body of molten materialand for separating said mold elements, means for severing the solidifiedmain casting body from the solid slug remaining in said entry-way, meansfor removing the main solid casting body from said mold, and means forejecting the said solid slug in said entry-way following the separationof the mold elements.

7. A casting machine comprising a mold having separable mold elementsdefining an enclosed mold cavity therebetween, an entry-way to said moldcavity in one of said mold elements, means for filling said mold cavitythrough said entry-way, means for severing the solidified main castingbody from the solid slug remaining in said entry-way, means forseparating said mold elements following solidification of the moldcavity contents, and for bringing said mold elements together, means forremoving the main solid casting body from said mold, means for ejectingthe said solid slug in said entry-way, means responsive to the actualseparation of said mold elements for automatically moving said ejectingmeans into position adjacent to said entry-way, and means forautomatically moving said ejecting means out of the way of said moldelements prior to the engagement thereof.

8. In a casting machine where the mold is inserted directly into a bodyof molten material to be cast, the improvement comprising a mold havingan open-top, dish-shaped outer mold body including sides and a bottomwall, the side walls being sutficiently high to project above thesurface of the said body of molten material, an entryway in the bottomwall of said outer mold body which communicates with the bottom of amold cavity within the mold, a mold cavity-forming member within saidouter mold body having walls defining the sides and top of said moldcavity which are made of a highly heat conductive material, at least theside walls of said latter member having a cooling medium circulatingtherein to cool the walls of the mold cavity other than the bottom wallthereof, the Wall defining the bottom of said mold cavity being saidbottom Wall of said outer mold body which is heated by virtue of itsdirect contact with the body of molten material.

9. In a die casting machine having a die element with an open bottommold cavity, and wherein said mold cavity has a portion undercut a smallamount for retaining the finished casting therein, an ejector pin forejecting the casting from the mold extendable downward into the saidmold cavity through an opening in the walls of the die element to forcea solidified casting out of the open bottom thereof, said ejector pinbeing spaced from the walls defining said opening, and a source of lowpressure coupled with the mold cavity through 18 the said space betweenthe ejector pin and the said Walls of said opening to effect theexhaustion of the air in the mold cavity so to draw molten material intothe mold cavity to fill same.

10. Casting apparatus comprising a die assembly having separable upperand lower die elements adapted when brought together to define a moldcavity therebetween which conforms in shape to the article to be cast,said lower die element being an open-top, dish-shaped element having afilling hole extending through the bottom thereof, said upper dieelement having an open bottom mold cavity which is closed by the lowerdie element but with the filling hole communicating with the cavity,means for positioning said lower die element alternately in and out ofcontact with a body of molten material with the top of the side wallsthereof extending above the level of the molten material and forpositioning said upper die element over and in engagement with thebottom of said lower element, means for raising said upper die elementout of said dish-shaped lower die element following the solidificationof the material in the mold cavity while maintaining the filling.opening in the same location with respect to the mold cavity that itoccupied during the flow of liquid metal through the opening into thecavity, and means for shearing solidified casting metal in the fillinghole from the solidified casting metal in the mold cavity by shiftingone die element with respect to the other die element.

11. In a casting machine, a pair of relatively movable mold elementsadapted to define a mold cavity therebetween, one of said mold elementshaving: an entry-way into the mold cavity through which molten materialenters the cavity, means for severing the solidified main cast ing fromthe slug remaining in said entry-way prior to removal of the castingfrom the mold, said means including means for moving one of saidrelatively movable mold elements in a direction transverse to the outletend of said entry-way to shear the entryway slug from the main castingbody, and means for automatically moving said mold elements into theirmold cavity defining position, and for moving the same into a positionto expose the solid-casting within one of the mold elements to permitremoval thereof from the mold.

12. In a casting machine, a pair of relatively movable mold elementsadapted to define a mold cavity therebetween, one of said mold elementshaving an entry-way into the mold cavity through which molten materialenters the cavity, means for severing the solidified main casting fromthe slug remaining in said entry-way prior to removal of the castingfrom the mold, means for automatically moving said mold elements intotheir mold cavity defining position, and for moving the same into aposition to expose the solid casting within one of the mold cavityelements to permit removal thereof from the mold, means for ejecting thesolid slug remaining in said entryway, means for moving saidslug-ejecting means opposite the mold element containing said entry-waywhen said mold elements are in said latter position, and means foroperating said slug-ejecting means when in said lastmentioned positionto eject slugs from said entryway.

13. Cast'ing apparatus comprising vertically separable upper and lowerdie elements defining a mold cavity therebetween, said lower die elementhaving an aperture therethrough which forms an entry-way to the moldcavity, said upper die element having a mold cavity open at the bottomand shaped to enable the ready removal of the article to be east throughthe open bottom thereof, first means for moving said upper die elementinto and out of covering engagement with said lower die element, meansfor bringing the aperture portion of the lower die element and a sourceof liquid metal together for the flow of liquid metal into the moldcavity through the aperture, and means for moving one of said dieelements laterally with respect to the other to shear the slug aaesnss'19 remaining in said entry-way from the remainder of the castingfollowing the solidification of the casting material in said' moldcavity, and means for retaining the solid casting in said upper dieelement following the separation of the upper and lower die elements.

14. Casting apparatus comprising an upright support member, ahorizontally extending frame member supported from said upright supportmember and being adapted to overlie an open top container containingmolten material to be cast, an assembly supported from said frame memberand movable in a horizontal direction relative thereto, said assemblyincluding a pan support member carrying an open top pan having anapertured bottom, a resilient member for holding said pan support memberin an upper position with said pan removed from the molten material insaid container, a vertically movable die element-carried by said framemember and having at least one mold cavity which is open at the bottomand being shaped to enable the ready removal of the article to be eastthrough the open bottom thereof, first means for moving said die elementdownward into engagement with the bottom of said pan with the pan bottomclosing the open bottom of the mold cavity in said die element and saidaperture in the pan bottom communicating with the mold cavity, saidfirst means further moving said die element and pan downward into themolten material in said container with the top of said pan above thesurface of the molten material in said container, second means forlaterally displacing said pan and die element following the completionof the casting operation and prior to the separation thereof forshearing the slugs remaining in said pan aperture from the remainder ofthe casting, third means for separating said die element from the panfollowing the complete solidification of the material in said moldcavity, fifth means for ejecting the slugs from said pan aperturefollowing the separation of said pan and die element, and sixth meansfor moving said fifth means into operating position over said panfollowing the separation of said die element from said pan, and formoving said fifth means away from said pan following the ejection of theslugs and prior to the engagement of the said die element with the pan.

15. The casting machine of claim 14 wherein one of the die elementsconstitutes an upper die element and the other die element constitutes alower die element, and the lower die element having said entry-waytherein, and said first control means includes a relatively stationarycontrol element and a movable control element that is movable with saidupper die element, said control elements making contact to actuate thefirst control means when said upper die element has been moved upwardfrom said lower die element to move said ejecting device between saiddie elements, the separation of said latter control elements occurringwhen the upper die element is moved downward toward the lower dieelement to actuat said first control means to move said ejecting devicefrom between the separated die elements.

16. A metal casting machine comprising separable die elements which,when brought into engagement, define a mold cavity having an entry-wayfor the flow of metal thereinto through the bottom of one of the dieelements, first means for moving said separable die elements into aposition wherein the die elements are in engagement and the bottom ofthe assembly is immersed in a body of molten material, said first meansalso being adapted to remove said die assembly from contact with thebody of molten material and to separate the die elements from each otherfollowing the solidification of the molten material in the mold cavityand said entry-way, an ejecting device for solidified casting metal fromsaid entryway, second means for moving one of said ejecting device anddie elements to a position where the ejecting device is in operativeposition between the separated die elements adjacent to the die elementhaving said entry way, third means for removing the main solid castingfrom the die element containing said entry-way upon separa tion of saiddie elements, first control means responsive to the separation of saiddie elements to actuate Said second means, and second control means forperiodically actuating said first means to move said die elements intothe body of molten material and for causing said first means to raisesaid die assembly from the body of molten material and to separate saiddie elements following the solidification of the molten material in saiddie cavity.

17. A casting machine comprising a mold having separable mold elementsdefiningan enclosed mold cavity therebetween, an entry-way to said moldcavity in one of said mold elements, means for filling said mold cavitythrough said entry-way, means for bodily moving said separable moldelements together to bring the mold element containing said entry-wayinto and out of a body of molten material, means for severing thesolidified main casting body from the solid slug remaining in saidentry-way following the removal of the mold from the body of moltenmaterial, means for separating said mold elements followingsolidification of the mold cavity contents and the removal of the moldfrom said body of molten material, and for bringing said mold elementstogether, means for removing the main solid casting body from said mold,and means for ejecting the said solid slug in said entry-way followingthe sepa ration of said mold elements.

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